Drill mounting



March 31,` 1964 E. H. KURT 3,126,754

DRILL MOUNTING Filed Oct. 13. 1960 l 2 Sheets-Sheet 1 EWALD h. KURT W HIS TTORNEY 2 Sheets-Sheet 2 Filed Oct. 13, 1960 lNvENToR EWALD H. KURT ToRNEY United States Patent O 3,126,754 DRILL MUNTHNG Ewald H. Kurt, Phillipshurg, N5., assigner te lingersoll- Rand Company, New York, NX., a corporation of New lersey filled Oct. 13, i960, Ser. No. 62,3@ 3 Claims. (Si. '7d-424.)

This invention relates to mountings for drills and particularly lfor percussive type rock drills in which the drill is advanced with respect to a stationary guide as the depth of hole increases.

The invention has for its object to provide an improved form of mounting in which the life of the parts will be increased and which tends to eliminate destructive shocks.

`Other objects and advantages o-f the construction will bein part obvious and in part pointed out in the following description of a preferred embodiment of the invention tak-en with the drawing wherein:

FIGURE l is a longitudinal elevational view of a mounting supporting a drill and its `drill rod, with the drill and drill rod being shown in dotted lines,

FlG. 2 is a section taken along the line 2-2 in FIG. 1 looking in the direction of the arrows,

FlG. 3 is a longitudinal axial section of the rear end of the mounting assembly,

FIG. 4 is a sectional View taken along the line 4--d in FlG. l looking in the direction of the arrows, and

FIG. 5 is an axial section of the front end of the drill mounting.

Referring to the drawing, the mounting includes a guide shell il@ upon which is mounted a conventional percussive `type rock drill l2 having a drill rod or steel 14 extending :forwardly thereof and guided by a suitable drill steel centralizer 16. Drill 12 is adapted to be advanced forwardly and be retracted by means of a suitable feed screw 1S adapted to be rotated by a motor Ztl.

Guide shell 1d is of the type having a base portion 22 provided with divergent side sur-faces 24 for engagement by a suitable clamp (not shown). Extending upwardly from base 22 are side portions 2id having grooves 21d to receive laterally extending ar-ms 3l? formed integrally with drill l2 to maintain drill y1.2 in position on guide shell lll as the drill moves lforwardly, as drilling progresses. Feed screw 18 is threaded at 32 to engage feed nut 34 carried by a boss 36 extending downwardly from the body of drill l2 and located between the upwardly extending portions Z6 of the guide shell. Feed nut 3d is held in place in boss 36 by a suitable nut 3% threaded thereon and extending rearwardly with respect to drill l2.

Feed screw 18 is alike at both ends and is adapted to be reversibly mounted in the guide shell. The mounting of its front end 4t) is shown in PTGS. 4 and 5. The front end 40 is provided with splines l2 slidingly engaged with a matingly splined socket of a cylindrical bearing dd fitting within the cylindrical bore 46 of a bracket 418. 'Ihe end of the bracket has a flange Sil secured to the end of guide shell lll by suitable cap screws 52'. rlfhe opposite or rearward end 54 of feed screw 18 is also spliued and flits into a splined socket 56 -of ya chuck 58y integrally formed with the shaft 60 of motor 2li. Shaft 6d is provided with a bearing 62 inserted in a flanged bushing 641- rest-ing against the casing portion 6d or motor 20. Interposed between chuck S8 and the casing shoulder d6 is -a thrust collar 68 encircling bushing 64 `and bealing against that bushing at its inner flat surface 7d. Chuck is provided with a flat face '72 against which the end of feed screw end S4 abuts and exerts thrust -in a rearward direction as `drill 12 advances.

The forward end 40 of feed screw 18` likewise has an 3,126,754 Patented Mar. 3l, T1964 2 end face 7d which bears against the flat inner surface 76 of bearing 44 for transmitting thrust of feed screw 18 in a fonward `direction as drill l2 advances. The resulting thrust on bearing dd is transmitted to bracket i8 by `the end face "7d of bracket d bearing against the bottom face 8d of bore d5.

As drill l2 reaches the end orf its rearward travel on shell lll, it strikes a spring buffer comprising a sleeve d2 siidingly mounted on the exterior of chuck 58 and projecting forwardly therefrom. Sleeve 'S2 is urged in its forward position by a coil spring 8f4 encircling chuck 5S and interposed between sleeve 32 and thrust collar 68. Spring '8d should be powerful enough to at least retard the rearward motion of drill l2 upon contact of sleeve S2 with ychuck nut 38. Sleeve S2 is held on chuck 53 by kinterengaging shoulders 36 and 83 on chuck 58 and sleeve d2, respectively.

lt will be seen that as drill l2 advances on lguide shell l@ by rotation of feed screw l engaging chuck Y53 of `motor 2d, feed screw 18 will be in compression and exert thrust against chuck 5d which transmits its lforce against thrust collar d3 and the motor casing 66 through the flanged bushing ed. There will be no thrust in motor 2l). Wear in the feed screw is generally greater on threads 32 during the forward motion of drill l2', and there may also be considerable wear on the splines at the rear end 54 of tfeed screw l. There will be substantially no 4wear at the front bearing ld nor on the front splined end 40l of feed screw 18, either in forward or backward motion of drill l2, and the splines at the front end remain su-bstantially new. Likewise the rear `face of threads 32 receives very little wear on the withdrawal of drill 112. The symmetrical arrangement, fore and aft, of feed screw ld enables it to be mounted alternately with either end engaged in the chuck 58 so that the majo-r wear on its threads can be distributed over both sides or faces of the threads, to provide it with substantially twice the norrnal life of a conventional feed screw used in a rock drill apparatus.

Thus, are accomplished among others, the advantages and objects hereinbefore referred to.

l claim:

1. A rock drill apparatus comprising: `a guide shell; a drill slidably mounted on said guide shell and adapted to be advanced along it; a rotary feed motor mounted on one end of said guide shell; a bearing mounted on the other end of said guide shell; a feed screw mounted on `and between said feed motor and said bearing and threadably engaging said drill for Iadvancing -it along said guide shell; and means for removably and alternately connecting either end of said feed screw in driven relationship to said feed motor, whereby said feed screw can be reversed end-fcr-end in Iits mountings on said guide shell to extend the wear life of said -ffeed scnew.

2. The apparatus of claim l wherein: both ends of said feed screw are splined and substantially identical; and said apparatus includes a splined socket on said feed motor arranged to `alternately receive either end of said feed screw.

3. The apparatus of claim 2 wherein said bearing includes a splined socket adapted to alternately receive either end of said feed screw.

References Cited in the file of this patent UNITED STATES PATENTS 1,626,568 Thomas Apr. 26, 1927 2,208,751 Dicker luly 23, 1940 2,341,472 OFarrell Feb. S, 1944 2,581,805 Maxson lan. 8, 1952 2,905,440 Gerentes Sept. 22, 1959 

1. A ROCK DRILL APPARATUS COMPRISING: A GUIDE SHELL; A DRILL SLIDABLY MOUNTED ON SAID GUIDE SHELL AND ADAPTED TO BE ADVANCED ALONG IT; A ROTARY FEED MOTOR MOUNTED ON ONE END OF SAID GUIDE SHELL; A BEARING MOUNTED ON THE OTHER END OF SAID GUIDE SHELL; A FEED SCREW MOUNTED ON AND BETWEEN SAID FEED MOTOR AND SAID BEARING AND THREADABLY ENGAGING SAID DRILL FOR ADVANCING IT ALONG SAID GUIDE SHELL; AND MEANS FOR REMOVABLY AND ALTERNATELY CONNECTING EITHER END OF SAID FEED SCREW IN DRIVEN RELATIONSHIP TO SAID FEED MOTOR, WHEREBY SAID FEED SCREW CAN BE REVERSED END-FOR-END IN ITS MOUNTINGS ON SAID GUIDE SHELL TO EXTEND THE WEAR LIFE OF SAID FEED SCREW. 